This invention relates to control systems for industrial lift trucks. In particular, it relates to control systems for so-called "walkie" industrial lift trucks.
A "walkie" industrial lift truck generally includes a set of controls such as those for lifting and lowering a load, for varying the direction and the speed of the truck and for activating a horn. Since the operator of the lift truck should have an easy access to the controls, the controls should ideally be located on or in the vicinity of the handle used to steer the truck. Various control systems for use in the industrial lift trucks are disclosed in the U.S. Pat. Nos. 3,465,841; 3,724,586; 3,300,612; 2,913,062; 2,957,536; 3,166,139; 3,529,689; 3,168,157; and 3,419,104.
The present invention provides an improved control system useful in industrial lift trucks.
Thus, one object of the present invention is to provide a lift truck control system which is compact and which permits access to all control functions by either or both hands of the operator while the hands are on the grip bars used for steering the truck.
Another object of the invention is to provide a lift truck control system which is easy and inexpensive to manufacture and to install.
A further object of the invention is to provide a control system for controlling the speed and the direction of a lift truck, which has a small number of moving parts and is therefore reliable and not susceptible to wear.
Still another object of the invention is to provide a lift truck controller which employs modular construction.
A still further object of the invention is to provide a controller for controlling the speed and the direction of a lift truck, which permits the selection of discrete predetermined rates of speed.
Other objects of the present invention will become apparent to those skilled in the art upon studying this disclosure.